ODBC Connector > Pushdown optimization > Pushdown optimization types
  

Pushdown optimization types

The Secure Agent applies pushdown optimization to a mapping when you select the Pushdown Optimization type in the advanced session property.
You can select the following pushdown types:

Source pushdown optimization

When you configure source pushdown optimization for a mapping, the Secure Agent analyzes the optimized mapping from the source to the target or until it reaches a downstream transformation that it cannot push to the source database.
The Secure Agent generates and executes a SELECT statement for each source that has transformation logic pushed down. Then, it reads the results of this SQL query and processes the remaining transformations in the mapping.
You can configure a mapping to use source pushdown if the source and target reside in different databases. For example, if a mapping contains a Teradata source and an Oracle target, you can configure source pushdown to push some transformation logic for processing to the Teradata source.

Target pushdown optimization

The task analyzes the mapping from target to source or until it reaches transformation logic that it cannot push to the target database.
The task generates an Insert, Delete, or Update statement based on the transformation logic for each transformation that it can push to the target database. The task processes the transformation logic up to the point where it can push the transformation logic to the database. Then, the task executes the generated SQL on the target database.

Full pushdown optimization

You can configure full pushdown optimization only when the source and target are in the same database.
When you configure full pushdown optimization, the Secure Agent attempts to push all transformation logic in the mapping to the target database. If the Secure Agent cannot push all transformation logic to the database, it performs both source-side and target-side pushdown optimization.
When you run a mapping configured for full pushdown optimization, the Secure Agent analyzes the mapping from the source to the target or until it reaches a downstream transformation it cannot push to the target database. It generates and executes SQL statements against the source or target based on the transformation logic it can push to the database.